A method of manufacturing a conventional module is described hereinafter with reference to FIGS. 12-14. FIG. 12 shows a flowchart illustrating a method of manufacturing the conventional module. FIG. 13A shows a top view of the conventional module at an injection step shown in FIG. 12. FIG. 13B shows a lateral view of the conventional module at the injection step shown in FIG. 12. The method of manufacturing conventional module 100, namely, a semiconductor mounted substrate, is described following the order of the steps shown in FIG. 12.
Application step S121 supplies solder 103 and flux 104 to substrate 102. Solder 103 is formed of cream solder. Mounting step S122 takes place after application step S121, and mounts chip component 105 as well as semiconductor element 106 to substrate 102. A clearance of approx. 0.5 mm is provided between chip component 105 and semiconductor element 106. Solder bumps (not shown) are provided to semiconductor element 106. Reflow step S123 takes place after mounting step S122, and melts solder 103 as well as the solder bumps for connecting chip component 105 and semiconductor element 106 to substrate 102.
Injection step S124 takes place after reflow step S123, and injects resin 110 into a gap between semiconductor element 106 and substrate 102, and then curing step S125 cures resin 110, thereby completing module 100. Conventional module 100 and the manufacturing method of module 100 discussed above are disclosed in, e.g. Japanese Unexamined Patent Publication No. H11-214586.
FIG. 14A shows a sectional view of chip component 105 of conventional module 100, and FIG. 14B shows a sectional view illustrating an essential part of a soldered section of chip component 105 of conventional module 100.
When the foregoing manufacturing method mounts chip component 105 closely to semiconductor element 106 with a clearance in between as close as 0.3 mm, resin 110 injected sometimes cover both of chip component 105 and solder 103. Since the gap between chip component 105 and substrate 102 is smaller than that between semiconductor element 106 and substrate 102, resin 110 is hard to enter into the gap between chip component 105 and substrate 102. Therefore, as shown in FIGS. 14A and 14B, void 115 where resin 110 is not filled is formed between chip component 105 and substrate 102. Then resin 110 sometimes covers both of chip component 105 and solder 103 although void 115 still exists.